Just saw this on E-Bay: http://www.ebay.com/itm/281211996229?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1438.l2649#ht_234wt_880
Original cool runner.. Produced by Oliver, sold thru the GSCA. The TA SPX is the same manifold, but considerably improved. Look carefully a the gasket/witness marks on that underside picture, you can see how far the ports were off. The one I worked on was also full of machining steps, that had to be smoothed out, but it did make more upper end power than any other Buick manifold, as does the SPX today. You just don't have to spend as much time with a grinder in your hand with the new one. JW
Also if I remember right, the carburetor pad is machined parallel with the head flanges. So, in a typical 4 to 6 "nose up" passenger car engine installation, the carb ends up being tilted rearward the same amount rather than sitting level. This was also corrected when TA took over production. Someone please correct me if this isn't the case. Devon